Have TRACTOR Pistons Changed In 50 YEARS?

[@JAMSIONLINE]

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[@blueovalfan23]

what about balance? we've had issues at work with ipd pistons having inconsistent weights. destroyed several blocks. doubt it'll help solve the issues at hand but it might be good to know.

[@domenicomonteleone3055]

I have a question what about the weight of the piston does that account to anything in what you have done in the process hi 👋 from # YSW 🇨🇦 where I follow you 💯 both !!

[@THEMOWERMEDIC1]

Preordered mine! Thanks For every one of your informative videos.

[@billygragg218]

😅j

[@bigal5747]

The only thing 2 machinists can agree on is... The 3rd machinist is doing it wrong

[@brandons9138]

Oh man. That is so right.

[@williamgrissom9022]

When a young grad student, I was in the engineering school machine shop and one machinist was fussing to me that another machinist was stupid to drill a large hole by slowly stepping up in drill size, as if I knew any better (no undergrad courses on machining nor shop). He said all you needed was a tiny pilot hole and the final drill would follow it straight down. Perhaps the hole ends up more centered that way, but I step up drill bits gradually at home. Maybe I could get by with a two-fer if my drill bits were ground perfectly but I just eyeball them on a grinding wheel when re-sharpening. At least they had a quality drill press which secured the parts, but drilling a hole on a milling machine or lathe would likely hold center better.

[@bigal5747]

@@williamgrissom9022 whatever gets the job done. At home you can do it however you want!

[@cm9247]

🤣

[@bobbywallacw323]

It's obvious that you've been in a shop that's had at least three Machinists ! 😂

[@DJ-bh1ju]

Love how you have such a respectful, professional relationship with your father. You both share such a love for what you do - and it shows in the interaction between you.

[@warbirdwf]

I love the fact that you invested the time to investigate this clearance issue further. I was hoping you would heat the pistons up to see the potential expansion differences and you did. Nice job to you both.

[@SightsNjunk]

I loved the banter. Always joking, with a bit of truth. Makes me think of my father. I love your videos, both for the information, and for the interactions and little stories.

[@JAMSIONLINE]

Thanks for watching!

[@randyhall2135]

Hey guys , you do incredible work. Was wondering if we could get a little update on how your Allis Chalmers engine rebuild is working out?

[@JAMSIONLINE]

Ran great this spring! Won't run again until this fall maybe or next spring.

[@domenicomonteleone3055]

​@@JAMSIONLINEi have a question to ask you both is there any way to weight the piston when you are doing the measurements so you could have a accurate reading yes or no hi from # YSW 🇨🇦 I love following you beacuse you open up many things I never knew about respect back to you both.

[@philstabile173]

Firstly i really enjoy watching your first rate machining your quality of work is second to none.an overfueling injector pump will send cylinder temps skyrocketing only "race spec"ring end gap could have survived such an event.

[@rickysmith8099]

You guys work great together never loose that with your pops I lost mine in 2006 it think of him every day stay safe my friends

[@riverwizard22]

Nice job..... I'm 76 retired from truck mech.... Love your videos..... You should be a proud dad.....

[@Stevie_D]

That was interesting - to measure is to know and cutting those pistons apart supplied a lot of useful information to your process ... and it was cool to see how they were made!

[@lovesloudcars]

I loved his comment about I've been telling you the whole time since you started this KZbin thing we're wasting time. Very funny I laughed.

[@tdkrei]

Science is always fun (for some of us). You mentioned that the old piston had TIn coating. As a retired machinist (CNC and Manual) I have had considerable experience wi9th this coating as well as others. The primary reason for TIn coating is lubrication. It's applied to carbide for that very reason not to have chip buildup on the cutting edge. I could have influence on the heat variation also on the wearing capabilities. Good video gentleman. Keep on smiling.

[@dennisyoung4631]

Tin, as in Sn - tin metal - VS “TiN, i.e. *Titanium Nitride?* The first is sort of a silvery color, vis Titanium Nitride (on, say, TPG222 inserts - what some of my lathe tooling takes) have more of a gold color.

[@kevind1865]

They most certainly were not coating tractor pistons with TiN in the 70's. He means actual elemental tin (Sn), as in tin cans.

[@tdkrei]

Wonderful!

[@tdkrei]

Pardon me for being so stupid.

[@tdkrei]

OK, let's put this in perspective, first I did not clarify nor state that, that was used in the 50's second I only suggested the purpose of Tin coating not anything to do with Alais tractors. Gees, give it a rest, please.

[@ryanp0342]

Great video. Just a recommendation when comparing and displaying data, graph it in a simple plot. Makes it a lot easier for people to see the differences.

[@Sherlock067]

Nice addition to the tool crib! Cleaning guy has got to get that cutting saw cleaned out ! Great information guys!👍

[@logancarter2134]

Watching y'all work and listening to y'all talk I had the realization that y'all and all the other people like you are the salt of the earth and what has made this country great and why it's worth fighting for.

[@MikeHarris1984]

10:50 that eagle is bad ass!!! Such a beautiful bird of prey! In Phoenix, we have a lot of Red Tail Hawks, Owls, Vulchures, and very fsr out, eagles. But you rearly will see an eagle ever. They have sanctuary areas at the lakes that are out in the middle of the desert. But i live in a 3 year old house i had built out in the edge of the city in the middle of the desert. My digs, i had to build a fenced in cage from air and land. The birds if prey around here is insane and owls, natures most perfect killer, get pets all the time. Hawks do too. But so different from living in the middle of the city. We also have bobcats, just caught one with kittens in my front yard the other night on cam, and big packs of coyotes. We then also have wild donkeys all over that walk down our streets.

[@TurboDog73TX]

Excellent detective work guys. I REALLY like that piston measuring tool.

[@cavsh00ter]

Love the way you take things apart and actually find out the whys and how comes TO COOL

[@brocluno01]

Well done. Old guy here. Have built a few engines in my time. I can say that ring gap kills more engines than anything other than bad lifters with flat tappet cams ... 🙃

[@PCMenten]

Very nicely done. Enjoyed how thorough you both were. 👍

[@cdnaudioguy]

Any science is good science. Thanks for taking the time to do this and get some real answers about what might be happening to the owners of these tractors.

[@terrancebarrett727]

Your dad is a legend! And your dad is making you one... learn all you can! Worked with my dad and learned all I could from him.. then he had a stroke and can't do what he loved to cars the same pace...

[@av8tore71]

I went to an estate sale and bought a couple Lycoming IO-360 aircraft engines and they came with boxes and boxes of spare parts. One of the boxes contained a MC-1 Measuring Center Base Kit

[@Awkward_Fox]

That's a hell of a grab! Probably wasn't a cheap estate sale pickup though. Hope the engines run well, and are going to good use keeping someone aloft!

[@av8tore71]

@@Awkward_Fox Im rebuilding one and donated the other to the local A&P school at the community college.

[@josephlawless6013]

Everything goes into the tolerance. The internal changes could also affect expansion and the reason they made the changes. As usual your assumptions are spot on with what you find. Any time you change from OEM there are changes. Even new OEM parts can have changes based on updates in everything.

[@mikekahl4745]

As a farmer and shade tree mechanic, i am in all with the skill both of you possess.

[@kellyslow5506]

This is quickly becoming my favorite channel on YT. Excellent work!

[@dadoVRC]

The main reason there's a steel or cast iron ring for the upper piston ring is to make a thermal barrier to it, to avoid or reduce cooking, and it's also useful to keep the groove shape to the right dimensions, to allow the ring to be pressurised by combustion gasses. Also, if the ring has a conical section, meant to "hammer" slightly in the groove to clean off combustion residues, the hard groove surface allow it to last a lot longer. The small dimensions of the embedded ring can't make any difference to thermal expansion of the aluminium, it is going to stretch when hot!

[@chuckg9805]

As Schultz said - very interesting. The real big deal is a clean empty work bench in the shop - that took some work. Thanks for the video's.

[@N57RU]

The one thing I would like to see is the difference in the ring groove depth diameter between the Old Old and the New Old pistons.

[@tpfromcentralpa1692]

As someone who uses these brand of parts in other engine makes, I am glad you sectioned the pistons, was neat to see. Does any other companys offer kits for 426 Allis's other than Reliance?

[@geraldparker1767]

Love how you guys present - thank you.

[@davidrfowler6432]

2 things that also require investigating are the original engine oil viscosity ( oil pressure ) and oil pump flow output , if you used a thinner oil then that might also be the part culprit. the oil pump gears may have been spaced larger to account for the thicker engine oil used during those periods to maintain correct oil pressure ( upwards or over 75 psi oil pressure was correct for engines ) i remember an old flathead ford V 8 showing 94 psi on the pressure gauge

[@mtut]

If you watch the teardown videos, the bearings looked like new. And even the old bearings looked pretty good for an old machine. They were getting plenty of pressure. Piston skirts are more or less splash-lubricated on this engine and if anything, a lower-viscosity oil would reach those parts sooner and lubricate as well, assuming sufficient film strength. The original engine probably called for 10W30 or 15W40 and those oils are still made and used widely. A 10W30 is the same viscosity today as it ever was. I don't quite remember what they were using for oil, but there's no indication they used anything lighter. And I haven't used a 5W40 or 0W40 synthetic in these, but again, even if they did, the bearings look beautiful and the rings and pistons should have been happy. I've seen engines that were diluted so bad there really was an oil pressure problem (injector pump that was leaking into the crankcase and washed the oil out through the breather). Bearings were spun; cylinders looked surprisingly good. There was also a lot of evidence that the injector pump was faulty and causing excessive heat in (some of) the combustion chambers. Supposedly the injector pump was overhauled while the engine was rebuilt, but the engine was rebuilt because of issues that pointed to a bad injector pump (cracked rings, scored pistons). And apparently after the overhaul the timing was off 180 degrees. I would guess that more than timing, the matter was due to cross-leaks in the pump that the overhaul didn't address - otherwise, why were some of the cylinders still in good shape while 3 of them were cooked? But they didn't get all the data they asked for from the company that rebuilt the injection pump the second time.

[@davidrfowler6432]

@@mtut that comment brings back a memory of a video i watched on youtube around 2009 , where a machinist was questioned why some farmers were removing the thermostats from their tractor engines , his reply was , tractor engines run hot ,sometimes very hot ,resulting in blown head gaskets ,removing the thermostats from the engines allows the engine coolant to be constantly cooled ,thus resulting in lower engine operating temperatures and less head gasket failures

[@kevin-vt7dw]

Where were you guys 40 years ago? I enjoy watching you now. You two make a great team

[@caseyjones1999]

this content is both entertaining and educational. Thanks for posting

[@Sheehy223]

😂

[@pudermcgavin4462]

I watch cei and stumbled on to you guys from him? I love machining it's so cool! And as a mechanic this makes me smile!

[@dirtyaznstyle4156]

That is some hot looking weather… as long as it’s not humid though. As a cold chisel aficionado nice seeing a set like that

[@bobbeazley2502]

Awesome in detail to get to the bottom of the problem.

[@SR-ml4dn]

Thanks for the video it was interesting to see. I'm curious about the piston grooves concentricity because together with the piston rings they will position the piston in the liner. For big ship engines we call that for scuffing when the piston grind against the liner wall. The piston rings are also coated with a soft metal compound that will wear up.

[@DarkVegetaman]

Shout out from the allis chalmers tractor forums. I enjoy reading about the 210 stuff but i only have a WD so I’m just a reader but it is all interesting. Nice video.

[@GNX157]

Great work. You should try and reach out to Lake Speed Jr at Total Seal Rings and maybe do an online consult. He really knows his stuff when it comes to pistons and especially end gaps on rings and how that affects engine performance.

[@MAIDENCOMMONRAIL]

Nice job...i think we dont take enough time to make some analisys of product or failure...but one thing is missing in your test...the thermal change on the cylinder sleeve itself Keep the good work

[@michaelferretti7869]

I have to say even though i know nothing about machine shops, I'm mesmerized watching your videos! I'm curious, how long does it take to machine a V8 block that just needs boring for oversized pistons?

[@rickpalechuk4411]

Pretty smart for custodial staff 😄 Cheers

[@spud435]

Interesting Back during the energy crunch the Government paid GM to do a study on when to replace parts for fuel savings. On the wheel bearing back then you repacked every brake change and inspected. The result were all over the place and rerunning the test decided to make half worn out bearing to speed up the test but that kind of tolerances could only be done in the lab. And much to their surprise they hadn't wore out by the end of the test. And after retooling with tighter tolerances half wore out no break in wheel bearing went from if your lucky 20,000 miles to 50,000. Bearing was the main fault in alternators but with the new bearing was still having problems. To tight of a belt puts to much side load and the answer the serpentine belt. All thanks to a small Gov study on fuel saving.

[@atariforever2002]

Absolutely fascinating. Love your channel guys. Keep them coming!

[@scottallpress3818]

Awesome video , was thinking about this engine issue again the other day . Glad it’s now sorted .

[@stephenpoe2037]

Interesting research . Time well spent . Thanks for sharing !

[@sammcbride2464]

Is this show about when I mentioned that forged pistons are different than cast pistons? I like the show. Cutting will not show the difference. You have to heat them and see the expansion properties. I commented prematurely. Awesome study. You guys are doing great stuff.

[@alistairshanks5099]

Great methodical fault analysis even though that was not the reason for the failure and it at least ruled it out and points to the ring gap theory. If the pump was causing over fueling and the crown of the piston was running hotter than it should have then the ring gap may be the answer. Another reason manufacturers could be running less clearance between pistons and bores is the improvement in lubricants as well as other improvements in metals and machining.

[@davidblalock9945]

I agree with your findings. Ring gap is my usual suspect when I have that kind of engine failure.

[@damianboyd]

Simply yes. As much as the technology around the engine has changed so has the internals, from tighter tolerances to better materials those engines have become more efficient, reliable and optimized.

[@randymagnum143]

There are a lot of aftermarket parts out there made out of whatever is on hand.

[@greggobleman270]

You mentioned the tin coating on the old pistons. Goldsmithterry in his comment also pointed out the lubrication of tin. It's like older USA made light bulbs. Tin and brass bulbs screw into their sockets easily. Modern Chinese made bulbs made from melded down Chevy's and Ford's will gall often times. Could that tin coating be important on the clearance issues?

[@terrancethayer124]

You two are great, and you have a wonderful wife / mother. Of course she also recognizes that the cleaning guy makes the pistons spotless before they are placed in her freezer or oven...

[@craigstrickland1572]

Safety squints work! OSHA approved!! I was squinting once trying to make a crush sleeve out of some junk metal for a gate wheel. Didn't get anything in my eyes....my chest caught on fire though with all the sparks but you didn't hear that from me!

[@chumbuddy100]

nice job looking at the geometry of the piston (skirt diameter across temperatures) . I did see a difference in the geometry (more / less material) of the skirt below the pin boss. this may make a difference in the thermal growth in that area and the stiffness of the skirt below the pin boss. the question of material type is still unknown. there are a lot of different alloys of aluminum.

[@tedmoss]

Expansion will likely be less in a harder alloy.

[@markchapman2585]

Edelbrock said aluminum went up 40% crazy. Great video guys keep up the great content cheers from Canada 🍻

[@jeremyking5684]

Your right ,always go by the piston manufacturers recommendations . Only time I go by oem specs is if I'm using oem made parts. Piston manufacturers have spent millions on testing to find the best clearance,for new materials

[@bcbloc02]

If you think Reliance has ever had one of these pistons in an engine and tested it I can about bet it likely never happened. They are in the parts copying and reselling business not the development business. With a portfolio that covers thousands of engines of tens of thousands of applications many of which have been obsolete for decades They probably could not come up with enough engines to test their products even if they wanted to.

[@Ham68229]

It's been a proven fact that today we use better materials than what was used say, 20-100 yrs ago. Great video. cheers :)

[@bwlyon]

I believe your hypothesis is correct. The new pistons do not grow as much when running at operating temps, and the first overhaul ring gap was to tight causing the engine failure. Live and learn. I’m confident you will never put an engine together without checking piston ring gap before installation. Love your content.

[@Mark-zz9rt]

Love listening to this stuff very relaxing to me.

[@zvondiesel]

Absolutely 💯 you can't go off old factory specs ,when using new manufactured parts myself I learned that expensive lesson aswell especially when building David brown engines

[@goosenotmaverick1156]

David brown, didn't they manufacturer some of those funny two wheel tractors at one point? I know there was a few companies that did, like gravely being the one I see most commonly. Probably not what you're working on, but just curious.

[@zvondiesel]

@@goosenotmaverick1156 David brown was with case tractor and dozer division and possibly with other companies

[@goosenotmaverick1156]

@@zvondiesel gotcha. The ones I'm thinking of I can't remember the name, so I'm trying to figure it out. Obviously not David brown then lol neat! I've been working on my neighbors Ford 6600 for a few years basically restoring it one bit at a time. It's been a buggar, I'm a car guy not a tractor guy, but it's been fun too. We started at the front and are working our way back lol front end (wear pins, bushing, wheel bearings, etc), engine (entire rebuild), new clutch kit, trans (all bearings and worn parts replaced), steering system (pump, gear, lines, linkages), pto clutch, hydro pump, spool valves for remotes. Eventually I'll have to dig into the brakes but for right now that's all functioning properly and adjusted. Dude has spent astronomical amounts of money thus far.

[@williamwertman24]

Im curious where you guys get your tolerance numbers from for your builds with the newer materials. Some are not so easy to find. I do some light rebuilds (more so assembly after machining) and want to get it to some more of the building and machining in house. I've done machine work in the past and really enjoyed it.

[@davidblalock9945]

Honestly, that you posted the video, regardless of the outcome, shows your dedication to the dissemination relevant information.

[@edsmachine93]

Great video guys. Nice evaluation and comparisons. Thanks for sharing. 👍

[@BruceBoschek]

Very interesting data and discussions. Thanks. One note on metrology: IR thermometers generally show very unreliable values on shiny metal objects. Also, when using an IR thermometer get as close to the surface to be measured as possible. The cone of detection is quite large so that at a distance you are measuring the desired object and a large amount of background. Sorry for the pedanticism. I'm an old, retired scientist.

[@glenurban3596]

GOOD JOB testing this and learning. BUT..... you need to check the cam grind and taper of the piston skirt to see the full picture. The cam ground skirt is a bit like a leaf spring, starting with narrow contact in the middle cold, as the piston heats up teh contact gets wider....which more contact COOLS the piston and it's almost like it regulates itself. You might already know... "four corner scuffing" is what happens when the springyness of the skirt runs out of travel. Far as Silicon content, the amount that the aluminum expands with heat is negligible difference one alloy to another, but the true difference is how much the piston MOVES heat down to the skirt, and how tight it CAN get before scuffing. LOW silicon pistons move heat fast and have POOR scuff resistance, so the skirt will expand more because it gets hotter, and will need to be looser because the material is more prone to scuffing. While a hyper piston the skirt will stay cooler, and can run tighter without scuffing. I'd love to talk with you guys sometime, tho I called once and did get a kick out of your answering service, which is fine, free time these days is a rare thing, but maybe in the future.

[@gregoryschmitz2131]

Love the series and not trying to argue but two things changed. Maybe the most significant was the fuel pump rebuilt 100% correct (and I did watch the assessment by the consulting injection pump people). The other of course is the ring gap. And its possible that the one issue and call the ring gap an aspect, combined to push the cylinder wall into overheat. Will never know of course and the right things were done, get the injection pump 100% correct and give a bit of more wiggle for the rings.

[@sfr2929]

I know in our race engines, a lot of the clearance is partially determined by the additive packs in the oil being used. Question is, would the oil used in the 70s vs today have anything to do with the clearance given by the books? Not saying the material difference in the alloy isnt a part of it as well.

[@timschjei3917]

You can bolt a plate of material using the rear guide holes and use the saw vertical.

[@tracydiller9378]

Nice job guys it just goes to show you go back to the manufacture that made the parts, and that's in really everything.

[@karlfischer1011]

50 years down the road, the original source may not be the same or exist at all. Allis Chalmers like International Harvester did much in house to avoid outsourcing (but i think around the 1970s started to go away from that concept). Also both Companies ceased to exist around 1985. Furthermore the other vendors such as Federal Mogul have gone thru multiple corporate changes and plant closures in 50 years--the part you buy today is not the same as the part 20 years ago. Some parts have been eliminated, others consolidated, and some cost-reduced. In some instances the part you get from completely unrelated brands is identical, the manufacturers do a lot of B2B trades and reboxing so they don't have to run a line for a small run with near zero demand. Good old days not always good and progress not always to the good.

[@tracydiller9378]

Good Point.@@karlfischer1011

[@stevekopito]

That QMP measuring system is awesome

[@valghyna7668]

as an old pirta band user, Im in live with your saw

[@iainburgess8577]

Thats interesting. I wonder if the block side of the tolerance window has a larger variance. But as you said, the manufacturing & quality control changes of the last 50 years are significant; but not something that can be tested adequately; you'd need a hundred or so samples for a limited test.

[@andrewklahold2880]

Yes but as to yesterday's quality today we would think parts should have better quality as to 50 yrs ago I have a 1957 D8 caterpillar that has cast ring lands and no tin coating was able to reuse all the Pistons with new wet sleeves new rings

[@iainburgess8577]

@@andrewklahold2880 exactly why I said tolerance & not quality. I know full well that for everything we do better today, there a way it's done worse because that's cheaper. Your example is the direct opposite of what Jamsi is dealing with, but the irony is that single examples never give the full picture. Your machine could have been from a mob W better quality control & tighter tolerances, or it could be the one best motor they ever build, at the whims of random chance. Jamsi could be the Worst for their make of tractor (tho they mentioned at least 1 other, so..), or a bad fluke. There's a Lot of maintenance issues that come back to cumulative tolerance interactions, that are simply troubleshot until the thing works Well Enough. We both know that D8 could never have been built to be that perfect after all that time; no more than the tractor was build to be a first of its kind failure. That's just not possible without large numbers of units for random chance to work with.

[@colingale]

In the 70's my late father worked for Champion graders, they had a situation where the new champion pistons where failing fast, my father worked out that the new pistons were heavier due to more mass, this retained heat more and expanded more are a result and resulted in slowballing of premature failing (champion themselves repeated that clearances were checked and are fine so thats not the issue) , downtime with million dollar mining equipment is never good so my dad went with his gut and drilled the pistons and reduced the mass, this fixed the issue and as a family we got a free holiday as thanks.

[@hiscifi2986]

The 1915 parts manual for BSA motorcycles states that a Cast-Iron Piston was an option back in the day. So we have moved on a lot since then. Honda die cast pistons were a major step forward from the old soft aluminium Hepolite machined pistons.

[@randymagnum143]

All the old Hondas I ever had had broken rings and smoked like the neighborhood mosquito patrol! On the other hand, *forged* aluminum tractor pistons? I've seen them with tens of thousands of hours on them.

[@tonyking9235]

THAT WAS VEREY INTERESTING THANKS BOYS

[@ty2010]

cylinder wash + tight rings + extra heat sounds like a winning combo

[@jamest.5001]

As it goes, the way I see it, you would been better off just keeping the pistons and sleeves, just get new rings, and hone the sleeves! Get them back to a round square! (Close as possible) and reassemble a loose engine, I have 'rebuilt' lawnmower engines doing less than that, I just honed the bore. Cleaned the rings with 320 sand paper. And reassembled the engine, and it was fine! It would barely run before, low compression, burned oil. And was almost like a new engine , I know a diesel is a lot different, and would only be a option, if you had zero other options, at best it would probably get you through a season or two! Possibly putting the rings in a oven at 350°f - 450°f for about 45 minutes, then quench may help put the spring back in the rings! Or warp them, so new rings is the better idea! (The better of bad ideas!)

[@shawnmcatee895]

The elimination of the Zinc from the oil is probably a greater factor than the growth factor of the piston material, or the rings butting.

[@leilanihayes787]

I am really surprised you did not compare the cam grind on the shirts of old and new piston.

[@georgenelson3496]

Super interesting, Great home brew science. Learning stuff

[@popswrench2]

listening while fixing my toilet .... 7040 i did , mid 1980s .... spec was .0025 - .005 ; (Piston cooling jets) , it ran few hundred hours well , until chisel plow in MUD , "squeeked" . one center Oring rolled out and cut , pushed in justa little . cleaned up measured , REsleeve/kit , we were going again . now MANY people remember the 301 specs 0045 - 009 , if memory serves . common aftermarket sizing is 006 - 007 avg. some 7000 needed conversion to oil jet bearing of 7010/7020 with the tight OEM kits . i had one such engine .

[@ronsherbert5757]

Like your videos, have learned some finer points of machining. That said you two are like the blind leading the blind. Solids expand like a photo enlargement, all dimensions by the same factor. So the greater the temperature difference and the longer the test dimension the better. Take your milling machine and mill true flats on the top of the pistons and the bottom of the skirt. Put pistons in Dry Ice or liquid Nitrogen for the low temp and use oven mitts to handle unit under test. High temp use boiling water that way the hot and cold containers can be next to measuring place, and you can measure and remeasure as many time as it takes to get a good repeatable numbers. After all the thermal expansion is in the order of 0.00024/ 1 degree C. We know the top of the piston will be hotter and expand more than the skirt. The difference in heat flow from the top of piston to cylinder walls may be a factor. Have NO clue how to check that. Keep on Trucking. Thanks ron

[@darrelschulte6214]

Glad to hear that the allis is running good now. I followed that thread on the allis chalmers forum. Seems like they were kind of tough on you

[@JAMSIONLINE]

I got sideways with “Dr. Allis” when I disagreed with him on a couple of things via email and he took it personal 🤣

[@darrelschulte6214]

@JAMSIONLINE Dr Allis knows probably as much about Allis as anyone, but I sure do get disappointed when he gets like that with folks like you

[@Churchkey83]

The shape of the lower end of the Piston where the older one is square and the newer one is rounded. that rounding is physically stronger than the sharp right angle and eliminates stressing fail point in the Piston skirt.

[@douglash3129]

I worked with people who though it was someone else's job to replace the coolant for the saw, and clean up after them!!

[@gazza116]

well done guys,a good explanation i feel.

[@ProSimex84]

Man, this was so machine nerd, and so good.

[@woodpurposedmechanic8299]

Not sure you are considering that piston's can have a different cam grind. Basically that's an oval shape. I had my own pistons made for my race cars back in the day and I had to specify a cam. I can't tell you that I know what is good and bad or how to determine a clearance from the cam spec. I knew what worked from the guys that I apprenticed with and the difference between the Venolia and Arias pistons popular at the time. The Arias pistons needed a lot more clearance. Damn those things made a lot of noise before the engine came to temp but if you didn't make those clearances loose you would have pistons that look your failed pistons in the video. I really need to find that old engine log book.

[@PinyonGear]

Incorrect piston sidewall clearance does not crack valves if they never make contact. Back to combustion temps and injection timing.

[@gratefultrucker7781]

Yup and a turbocharged non after cooled non piston cooled engine can be fine but it has much less margin for error on heat.

[@allenhanford]

I rebuilt a 1973 Harley Sportster using the specs from the manual. After 500 miles of gentle use I got on it and the front piston seized. I talked to the Harley shop and they said "the factory manual is wrong. You need to use the clearance in the factory manual ADDENDUM".

[@brandonclifton2027]

Happy birthday to the big guy!🎉🎉🎉

[@lesotwell3561]

I believe he is correct, I think the injection pump problem combined with the ring end gap killed it. Had the pump not had a problem it may have been fine, hard to say.

[@TheLittlered1961]

I made a few pistons in my life and I believe I made a few of those pistons. When we measured them it had to be between 68 and 70 degrees. Between the top and. Bottom of the skirt there's supposed to be 0.001 of an inch difference for most pistons. Some of the Ford and AMC pistons are different. The rate of change for that piston should be about 0.0001 inch per 2 degrees above or below 70 degrees.. For our pistons, the tolerance is 0 to - 0.0005 of an inch.

[@MikeHarris1984]

I trust your guys is findings of anybody else's. Everybody online is just a keyboard warrior who thinks that they know everything because they watch the video somewhere. And someone might be an actual expert in the field and some did come forward and actually help you guys out to find the real issue. But many are not and just those warriors who think that they are the smartest person in the room because they watch the video somewhere sometime. But you can't see a lot of things through a video and feel and with the video you only get the gist of what happened or during the time frame not the 100 plus hours put into it broken down into a 15 minute video. But I think you guys keep reiterating and going through even more data showing and proving that all these keyboard warriors are wrong is really good justification and hopefully get them to finally shut up. Because you guys know the experts in this field and when you need help you reach out and get help from other shops and things and so KZbin has been a great thing for that. But you guys do some amazing work. Makes me wish I lived over that way because I have an LS2 that they need to get fully machined and decked and gone thru. Where my plans are to build a big high horsepower naturally aspirated engine for my '05 GTO and there's just been sitting in the garage for the last couple years. Now that I have a C7 for my daily driver I can take my GTO and really deck it out have fun drag car out of it

[@rereg543]

Love these sorts of videos!

[@Dalbayob69]

Love this type of format for the video. I’m in Europe and use metric system so all I hear is random numbers 🤣 but still enjoyed watching this.

[@JAMSIONLINE]

Lol to sum it up, the new piston expanded .03MM less than the old piston from cold to hot 😝

[@rvarsigfusson6163]

@@JAMSIONLINE .03 mm is like a hair on your head. Just to say.

[@randyvilleneuve4907]

When I built my 360 Dodge magnum I used 4" diameter Hypereutectic pistons with a piston to bore clearance of .0015-.002. I have had no issues with the engine and it burns no oil. So I do not believe you had a clearance issue but every engine is different. Was your bore too smooth so oil retention was low? Its hard to get an answer on what hone grit to use but it appears for cast rings its between a 180 and 220 grit. My manual for my John Deer 3 cylinder Yanmar specifically called for a 180 grit ball hone which I used and had no issue with it.

[@LHW-kg9cp]

Really enjoy your videos! I'm curious, how wear is there in ID of cylinder in ring travel area of cylinder? IE, were could you have honed original sleeves and just installed new rings instead of using all new?

[@timrussell1559]

Great in depth video, just not sure the data collected at around 300 degrees really tells the tale. Considering, a diesel piston normally operates at 800 + degrees. Would have loved to see the average expansion rate at temps closer to that range, but, it's certainly understandable that heating a piston to a consistant 800 degrees in an average machine shop would be an extremely difficult task to perform, indeed. Very informative nonetheless!